Steam-heating plant



Aug- 22, 1944. 4H. APPEL 2,356,372

STEAM HEATING PLANT x Filed Mach 1Q 1941 v Ynn/ETJITOR; HANS APPEL PER ATTORNEY.

Patented Aug. 22, 1944 STEAM-HEATING PLAN T'y Hans` Appel, Prague, Czechoslovakia; vested in. the Alien Property Custodian Application March 1, 1941, Serial No. 381,240 In Bohemia-Moravia February 16, 1940 7 Claims.

The present invention relates to a low-pressure steam heating system provided with a pressurecontrolled steam generator plant particularly adapted for railway vehicles. The steamheating plant consists of a heated boiler and an automatically operating device for maintaining the boiler pressure within certain limitations. The

radiators connected to the boiler are, by meansof a distributing pipe, in communication with the steam space of the boiler, so that the same steam pressure prevails in all the radiators as in the boiler, whereby by maintaining the steam pressure uniform simultaneously also the temperature of the heating surfaces of the radiators isn controlled. The steam generating plant the pressure of which is controlled according to the invention forms the regulator for the temperature of the heating surfaces of the radiators.

Anobject of the pres-ent invention is to so construct a low-pressure steam heating plant that the radiators may be supplied with controlled low-pressure steam from a source of high-pressure steam which is not provided on the vehicle itself. As will be presently explained, the high pressure steam is supplied to the vehicle from the outside source when the vehicle is in use.

According to the invention a thermostatically controlled throttle Valve is provided inv the connecting pipe between the high-pressure steam pipe carrying steam, for example from the locomotive, and the distributing pipe supplying the pressure-controlled steam from the low-pressure steam boiler which may be provided on the vehicle to the radiators. The thermostat of said throttle valve is inuenced by the temperature of the heating medium discharged by the radiators. If the low-pressure steam heating system is connected to the high-pressure steam pipe, the high-pressure steam flows through said automatically operating throttle valve. In accordance with the setting of the thermostat the highpressure steam is changed to low-pressure steam of quite a deinite pressure and fills the radiators maintaining uniform the temperature of their heating surfaces. When heating with steam of a source of high-pressure steam the. same Working condition of the radiators results as when the heating plant is operated with steam produced in the individual pressure-controlled lowpressure steam generator. l

In the connecting pipe between, theV high-pressure steam pipe and the above mentioned thermostaticallycontrolled throttle valve a check valve is arranged according tothe invention. Whichis opened by the high;pressuresteam. It

is kept closed as long as the low-pressure steam generator plant operates. The check valve may be provided with electrically operated means Dressing it with great forceA to its seat when the low pressure boiler is taken into operation so that entrance of high pressure ste-am into the plant at an undesired moment is positively prevented.

As during heating with high-pressure steam from the steam main and supplying the steam throttled by the above mentioned thermostatically controlled throttle valve to the radiators, a portion of the steam, without flowing through the radiators, reaches the low-pressure boiler and the thermostat of the :above mentioned throttle valve and may iniluence the operation of the latter, it is preferable to arrange in the distributing pipe of the heating plant, between the discharge point of the connecting pipe supplying the heating plant by Way of the throttle Valve with controlled steam, and the low-pressure Steam boiler, a valve which is influenced Iand closed by the pressure of the high-pressure steam. When high-pressure steam is supplied to the heating plant, this Valve cuts off the Way leading from the steam main to the 10W-pressure steam boiler and an undesired admission of steam to the thermostat of th'e above mentioned throttle valve is rendered impossible.

It is also of advantage to connect the casing of the throttle valve and the casing of the check valve, controlled electromagnetically in most cases, and also, the last mentioned pressure controlled valve in a heat conducting manner, so as to have a mutual thawing up effect by heat conduction and heat radiation. As is well known, during frost such constructional members of the steam generator plant may freeze. Each of these constructional members, therefore, is so formed that on being supplied with steam it thaws up and is rendered capable of operation.

If all such constructional members are in a heat conducting manner connected to each other, each constructional member supplied with steam safely thaws up. Hereby the heat also is transmitted to the other constructional members, so that these without steam being supplied to them also thaw up and are rendered capable of operation.

In the accompanying drawing a heating plant according to the invention is diagrammatically shown by Way of example.

In this drawing:

Fig. l is a diagrammatic lay-out of a plant ac cordingtothe present invention,

Fig. 2 is a diagrammatic illustration of the change-over switch shown in Fig. 1,

Fig. 3 is a diagrammatic showing of the switch illustrated in Fig. 2 in another switching position.

From the Zone of the lowest water level of the lowpressure steam boiler I of the heating plant according to Fig. 1 the stand-pipe 4, connected to the branch pipe 56, leads upwardly above the water level of a highly located tank 24. The boiler I is heated by the electric heating element 80 which is connected to a source of strong current by means of conduits 'I5 and 16. u

The steam space of boiler I is connected with radiators I9 by a steam main 20 and the pressure in the radiators is substantially the same as that in the boiler. To enable the boiler I of small water capacity to supply a great number of radiators the following automatic feed water supply system is proposed:

Float I6 in boiler I operates by means of a connecting rod I6' and electric switch 45. In the position shown in Fig. 1 the float is in its uppermost position and switch 45 connects contact points H and III. Current ows from battery 13, usually the light battery of the car, through conduit |0I, branch point |02, conduit |03, contact member b of hand switch I0 which is in position II shown in Fig. 1, conduit |04 to branch point |05, therefrom through conduit |06, contacts |01 and |08 of a bimetal thermostat 'I2 which responds to the temperature in the room to be heated, through conduit |09, contacts IIO and II I, conduit I I2, coil I I3 of a solenoid switch 14 which controls the current supply to heating element 80, conduit H4, contact member c of switch 10, conduit H5, branch point IIB, and conduit II'I back to battery 73. The solenoid coil I|3 is energized and switch I4 is closed and current is supplied to element 80.

The pressure of the steam now produced in boiler I is determined by the elevation of the water level in stand pipe 4. Finally water will be pressed through the stand pipe into tank 24 and the water level in the boiler sinks whereby iloat I6 removes switch 45 from contacts IIO and III and connects contacts II8 and II9. Thereby current supply to solenoid coil II3 is interrupted and thereby also the current supply to element 80 is interrupted and no further steam is produced and the boiler pressure is reduced.

At the same time the following electric circuit is established: battery 13, conduit IOI, conduit |03, contact element b of switch l0, conduits |04 and |20, solenoid coil of electrically operated valve 40, conduit |2I, contact points IIB and H9, conduits |22 and H4, element c of switch 10, conduits !I and II'I, battery T3. As long as no current is supplied to valve 40 it is closed under the iniluence of spring 46. With the circuit just described, closed valve 40 is opened and feed Water flows through pipe 4l into stand pipe 4 until the water level in the boiler again reaches its upper limit and switch 45 is brought back into the position shown in Fig. 1. The current supply to valve 40 is interrupted and the valve closes and normal steam generation goes on. The condensate returns from the radiators I9 to the boiler I by way of a pipe 48. To aerate the heating plant, a thermostatically controlled valve 50 is provided which is closed as soon as, on heating, the air in the plant is displaced by the steam and the latter has heated the thermostat of valve 50.

In order to allow the operation of such a heating plant with controlled low pressure steam derived from a source of high-pressure steam, preferably steam from a locomotive boiler, as is required in connection with railway vehicles, main steam pipe 30, extending below the vehicle and carrying the high-pressure steam when the vehicle is in use, is, in accordance with the present invention, connected to the distributing pipe 20 of the low-pressure steam generator plant by way of a connecting pipe 3| in which a throttle valve 60 is arranged. The latter is controlled by a thermostat 6I subjected to the temperature of the heating medium leaving the radiators I9 by way of the pipe 48, whereby the extensions by heat of the thermostat are transmitted by way of a rod 61, a lever 68 and an extension rod 60 to the valve 60 in such a manner that by way of the pipe 20 only so much steam iiows to the radiators I9, that a predetermined pressure is maintained in these radiators and, therefore, also the temperature of the heating surfaces of said radiators is maintained uniform. If, therefore. the pipe 36 is supplied with high-pressure steam, the radiators I9 are, by means of the steam supplied to them from the source of high-pressure steam, heated in exactly the same controlled manner as by the pressure-controlled steam ad mitted to them after connecting the low-pressure steam boiler I.

In the connecting pipe 3| a check valve 62 is provided which is opened by the pressure of the high pressure steam. In case there is no high pressure steam valve 62 closes the connection between the low pressure heating plant and the high pressure conduit 30. For starting up the low pressure boiler I which is mounted on the vehicle to be heated, switch I0 is brought to position II shown in Fig. 1. For operating the plant with steam from the high pressure conduit 30 switch 'I0 is moved to position I shown in Fig. 2. In this position contact member c of switch 10 closes the following circuit: battery 13, conduit II, member c, conduits I24 and |26, contact thermometer II exposed to the room temperature and closing its contacts upon reaching a predetermined temperature, conduits |21 and |29, coil |30 of a solenoid operating check valve 62, conduits |3I and III, battery 13. With this arrangement check valve 62 is pressed to its seat whenever the temperature in the room to be heated has reached a desired value and steam supply from the high pressure conduit is interrupted.

When switch 1u is in position 1I and boer l' is in operation, the circuit including coil |30 remains closed. As shown in Fig. 1, contact element b short-circuits thermometer 'II in the circuit described in the paragraph next above and coil |30 is always energized and valve 62 always pressed to its seatso that no steam can pass from the high pressure conduit 30 through valve 62 into the heating system as long as this is supplied with steam from the low pressure boiler I. To prevent, during operation with high pressure steam from throttle valve 60, a portion of the pressure-reduced steam to floW into the boiler I and from the latter either to escape by way of the stand-pipe 4 or to advance into the pipe 48 and to heat the thermostat 6I of the throttle valve 60, thereby disturbing the desired throttle operation, a stop valve 63 is provided in the distributing pipe 20 'between the discharge point of the connecting pipe 3| and the boiler I.

. The stop valve 63 is influenced in an opening sense by a spring 66 and is closed by the piston 05 disposed in cylinder 65', when high-pressure steam is admitted to the latter from the pipe 3U by way of the pipe 64. Valve 63 disconnects steam main from boiler I whenever the system is operated with steam from high pressure conduit 3U. No steam can pass from the reducing valve 60 through conduit 20 into boiler I. rIhe steam must pass through the radiators I9, condensate conduit 48 and thermostat 6I into boiler I and is stored therein and possibly tank 24 for future use.

If the vehicle provided with the low pressure system according to the invention is taken out of service switch 'It is brought to position 0 shown in Fig. 3 and no circuit is closed by said switch.

For draining the system a thermostat 44 of said valve is provided with a heating coil 43. As long as the device is cold, valve 44 is open. As soon as boiler I is started by turning switch I to position II, or the system is connected with a source of high pressure steam by turning switch 'I0 to position I, in both cases a circuit is closed for supplying heating coil 43 with current so that thermostat 44 is heated and valve 44 is closed. In position Il'. of the hand operated switch 'I0 the circuit is closed by contact element a and current flows from battery i3 through conduit IBI, member a, conduits |24 and |33, heating coil 43, conduits |34 and II'I, and back to battery 13.

If the system is supplied with high pressure steam the beforementioned circuit is closed by means of element c as shown in Fig. 2. If switch I0 is in position IJ the circuit is interrupted.

It may easily be seen that the constructional members, i. e. the throttle valve 66, the magnetic valve 62 and the stop member 63 may be arranged in a common casing or may otherwise be connected to each other as desired in a heat conducting manner. If after putting the vehicle out of service, all these constructional elements are frozen in and if for instance high-pressure steam is admitted through the pipe when the vehicle is put in service, the magnetic valve 62 is supplied with steam and thaws up. The heat, however, also is transmitted to the other constructional members 60 and 63 so that these also thaw up and are rendered capable of operation. Putting in service of the low-pressure steam boiler I has the same effect but then steam is admitted to the stop member 63 which thaws up, whereupon the heat is transmitted to the constructional members 60 and 62 by conduction and radiation.

What is claimed is:

1. A heating system for a vehicle comprising, in combination, a low pressure steam boiler mounted on the vehicle and comprising an automatic pressure control means connected to and maintaining a predetermined low pressure in the boiler, a low pressure steam main connected with the steam space of said boiler, a plurality of radiators connected for steam flow with said steam main, a high pressure steam conduit receiving high pressure steam from a source outside of the vehicle, a connecting conduit connecting said low pressure steam main and said high pressure steam conduit, a throttle means in said connecting conduit, a collecting conduit connected with said radiators and with said boiler and providing a. continuously open passage between said radiators and said boiler, and temperature responsive means connected with said collecting conduit and with said throttle means and being responsive to the temperature of the medium in said collecting conduit and operating said throttle means in accordance with the temperature of the medium discharged by said radiators,

2. A heating system as claimed in claim 1 including in the combination a feed water tank disposed on the vehicle at an elevation above said boiler and being connected for feed Water ow with the water space of said boiler, and a stand pipe connected With the water space of said boiler and extending and being open to the atmosphere above the water level of said tank and constituting said automatic low pressure control means.

3. A heating system as claimed in claim 1 including in the combination a check valve inserted in said connecting conduit between said high pressure steam conduit and said throttle means and adapted to open under the influence of high pressure steam for providing a passage for the high pressure steam to said throttle means.

4. A heating system as claimed in claim 1 including in the combination remotely controllable valve means in said connecting conduit between said high pressure steam conduit and said throttle means, boiler operation control means operatively connected with said boiler and with said valve means and denitely closing said valve means when said control means are set for normal operation of said low pressure boiler.

5. A heating system as claimed in claim 1 including in the combination electrically controllable valve means in said connecting conduit between said high pressure steam conduit and said throttle means, electric boiler operation control means, and electric switch means electrically connected with said boiler operation control means and with said electrically controllable valve means and effecting definite closure of said valve means when said switch means are set for normal operation of said boiler.

6. A heating system as claimed in claim 1 including in the combination a stop valve in said low pressure steam main between said boiler and the point where said connecting conduit is connected with said steam main, and a pressure responsive means connected with and operating said stop Valve and connected with and responsive to the pressure in said high pressure steam conduit and denitely closing said stop valve when there is pressure in said high pressure conduit.

7. A heating system as claimed in claim 1 including in the combination a check valve in said connecting conduit between said high pressure steam conduit and said throttle means and open` ing under the inuence of the high pressure steam and forming a passage for said steam to said throttle means, a stop valve in said 10W pressure steam main between said boiler and the point where said connecting conduit is connected to said steam main, and pressure responsive means connected with and operating said stop valve and connected with and actuated by the pressure in said high pressure steam conduit and closing said stop valve under the inuence of the high pressure steam.

HANS APPEL. 

